[WIP] Add mod api

6 files changed, 317 insertions, 0 deletions

diff --git a/src/main/kotlin/moe/nea/firmament/apis/ingame/FirmamentCustomPayload.kt b/src/main/kotlin/moe/nea/firmament/apis/ingame/FirmamentCustomPayload.kt
new file mode 100644
index 0000000..34e39ab
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/apis/ingame/FirmamentCustomPayload.kt
@@ -0,0 +1,36 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.apis.ingame
+
+import io.netty.buffer.ByteBuf
+import net.minecraft.network.codec.PacketCodec
+import net.minecraft.network.packet.CustomPayload
+import net.minecraft.util.Identifier
+
+interface FirmamentCustomPayload : CustomPayload {
+
+    class Unhandled private constructor(val identifier: Identifier) : FirmamentCustomPayload {
+        override fun getId(): CustomPayload.Id<out CustomPayload> {
+            return CustomPayload.id(identifier.toString())
+        }
+
+        companion object {
+            fun <B : ByteBuf> createCodec(identifier: Identifier): PacketCodec<B, Unhandled> {
+                return object : PacketCodec<B, Unhandled> {
+                    override fun decode(buf: B): Unhandled {
+                        return Unhandled(identifier)
+                    }
+
+                    override fun encode(buf: B, value: Unhandled) {
+                        // we will never send an unhandled packet stealthy
+                    }
+                }
+            }
+        }
+
+    }
+}
diff --git a/src/main/kotlin/moe/nea/firmament/apis/ingame/HypixelModAPI.kt b/src/main/kotlin/moe/nea/firmament/apis/ingame/HypixelModAPI.kt
new file mode 100644
index 0000000..460df91
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/apis/ingame/HypixelModAPI.kt
@@ -0,0 +1,56 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.apis.ingame
+
+import net.minecraft.network.packet.c2s.common.CustomPayloadC2SPacket
+import net.minecraft.text.Text
+import moe.nea.firmament.annotations.Subscribe
+import moe.nea.firmament.apis.ingame.packets.PartyInfoRequest
+import moe.nea.firmament.apis.ingame.packets.PartyInfoResponse
+import moe.nea.firmament.commands.thenExecute
+import moe.nea.firmament.events.CommandEvent
+import moe.nea.firmament.events.FirmamentCustomPayloadEvent
+import moe.nea.firmament.events.subscription.SubscriptionOwner
+import moe.nea.firmament.features.FirmamentFeature
+import moe.nea.firmament.features.debug.DeveloperFeatures
+import moe.nea.firmament.util.MC
+
+
+object HypixelModAPI : SubscriptionOwner {
+    init {
+        InGameCodecWrapper.Direction.C2S.customCodec =
+            InGameCodecWrapper.createStealthyCodec(
+                PartyInfoRequest.intoType()
+            )
+        InGameCodecWrapper.Direction.S2C.customCodec =
+            InGameCodecWrapper.createStealthyCodec(
+                PartyInfoResponse.intoType()
+            )
+    }
+
+    @JvmStatic
+    fun sendRequest(packet: FirmamentCustomPayload) {
+        MC.networkHandler?.sendPacket(CustomPayloadC2SPacket(packet))
+    }
+
+    @Subscribe
+    fun testCommand(event: CommandEvent.SubCommand) {
+        event.subcommand("sendpartyrequest") {
+            thenExecute {
+                sendRequest(PartyInfoRequest(1))
+            }
+        }
+    }
+
+    @Subscribe
+    fun logEvents(event: FirmamentCustomPayloadEvent) {
+        MC.sendChat(Text.stringifiedTranslatable("firmament.modapi.event", event.toString()))
+    }
+
+    override val delegateFeature: FirmamentFeature
+        get() = DeveloperFeatures
+}
diff --git a/src/main/kotlin/moe/nea/firmament/apis/ingame/InGameCodecWrapper.kt b/src/main/kotlin/moe/nea/firmament/apis/ingame/InGameCodecWrapper.kt
new file mode 100644
index 0000000..0720dbf
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/apis/ingame/InGameCodecWrapper.kt
@@ -0,0 +1,51 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.apis.ingame
+
+import net.minecraft.network.PacketByteBuf
+import net.minecraft.network.codec.PacketCodec
+import net.minecraft.network.packet.CustomPayload
+
+class InGameCodecWrapper(
+    val wrapped: PacketCodec<PacketByteBuf, CustomPayload>,
+    val direction: Direction,
+) : PacketCodec<PacketByteBuf, CustomPayload> {
+    enum class Direction {
+        S2C,
+        C2S,
+        ;
+
+        var customCodec: PacketCodec<PacketByteBuf, FirmamentCustomPayload> = createStealthyCodec()
+    }
+
+    companion object {
+        fun createStealthyCodec(vararg codecs: CustomPayload.Type<PacketByteBuf, out FirmamentCustomPayload>): PacketCodec<PacketByteBuf, FirmamentCustomPayload> {
+            return CustomPayload.createCodec(
+                { FirmamentCustomPayload.Unhandled.createCodec(it) },
+                codecs.toList()
+            ) as PacketCodec<PacketByteBuf, FirmamentCustomPayload>
+        }
+
+    }
+
+    override fun decode(buf: PacketByteBuf): CustomPayload {
+        val duplicateBuffer = PacketByteBuf(buf.slice())
+        val original = wrapped.decode(buf)
+        val duplicate = direction.customCodec.decode(duplicateBuffer)
+        if (duplicate is FirmamentCustomPayload.Unhandled)
+            return original
+        return JoinedCustomPayload(original, duplicate)
+    }
+
+    override fun encode(buf: PacketByteBuf, value: CustomPayload) {
+        if (value is FirmamentCustomPayload) {
+            direction.customCodec.encode(buf, value)
+        } else {
+            wrapped.encode(buf, value)
+        }
+    }
+}
diff --git a/src/main/kotlin/moe/nea/firmament/apis/ingame/JoinedCustomPayload.kt b/src/main/kotlin/moe/nea/firmament/apis/ingame/JoinedCustomPayload.kt
new file mode 100644
index 0000000..c673264
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/apis/ingame/JoinedCustomPayload.kt
@@ -0,0 +1,25 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.apis.ingame
+
+import net.minecraft.network.packet.CustomPayload
+
+/**
+ * A class to smuggle two parsed instances of the same custom payload packet.
+ */
+class JoinedCustomPayload(
+    val original: CustomPayload,
+    val smuggled: FirmamentCustomPayload
+) : CustomPayload {
+    companion object {
+        val joinedId = CustomPayload.id<JoinedCustomPayload>("firmament:joined")
+    }
+
+    override fun getId(): CustomPayload.Id<out JoinedCustomPayload> {
+        return joinedId
+    }
+}
diff --git a/src/main/kotlin/moe/nea/firmament/apis/ingame/packets/PartyInfoRequest.kt b/src/main/kotlin/moe/nea/firmament/apis/ingame/packets/PartyInfoRequest.kt
new file mode 100644
index 0000000..2b3d234
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/apis/ingame/packets/PartyInfoRequest.kt
@@ -0,0 +1,134 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.apis.ingame.packets
+
+import io.netty.buffer.ByteBuf
+import java.util.UUID
+import net.minecraft.network.PacketByteBuf
+import net.minecraft.network.codec.PacketCodec
+import net.minecraft.network.codec.PacketCodecs
+import net.minecraft.network.packet.CustomPayload
+import net.minecraft.util.Uuids
+import moe.nea.firmament.apis.ingame.FirmamentCustomPayload
+
+interface FirmamentCustomPayloadMeta<T : FirmamentCustomPayload> {
+    val ID: CustomPayload.Id<T>
+    val CODEC: PacketCodec<PacketByteBuf, T>
+
+    fun intoType(): CustomPayload.Type<PacketByteBuf, T> {
+        return CustomPayload.Type(ID, CODEC)
+    }
+}
+
+data class PartyInfoRequest(val version: Int) : FirmamentCustomPayload {
+    companion object : FirmamentCustomPayloadMeta<PartyInfoRequest> {
+        override val ID = CustomPayload.id<PartyInfoRequest>("hypixel:party_info")
+        override val CODEC =
+            PacketCodecs.VAR_INT.cast<PacketByteBuf>()
+                .xmap(::PartyInfoRequest, PartyInfoRequest::version)
+    }
+
+    override fun getId(): CustomPayload.Id<out CustomPayload> {
+        return ID
+    }
+}
+
+sealed interface PartyInfoResponseV
+sealed interface HypixelVersionedPacketData<out T>
+data class HypixelSuccessfulResponse<T>(val data: T) : HypixelVersionedPacketData<T>
+data class HypixelUnknownVersion(val version: Int) : HypixelVersionedPacketData<Nothing>
+data class HypixelApiError(val label: String, val errorId: Int) : HypixelVersionedPacketData<Nothing> {
+    companion object {
+        fun <B : ByteBuf> createCodec(label: String): PacketCodec<B, HypixelApiError> {
+            return PacketCodecs.VAR_INT
+                .cast<B>()
+                .xmap({ HypixelApiError(label, it) }, HypixelApiError::errorId)
+        }
+    }
+}
+
+object CodecUtils {
+    fun <B : PacketByteBuf, T> dispatchVersioned(
+        versions: Map<Int, PacketCodec<B, out T>>,
+        errorCodec: PacketCodec<B, HypixelApiError>
+    ): PacketCodec<B, HypixelVersionedPacketData<T>> {
+        return object : PacketCodec<B, HypixelVersionedPacketData<T>> {
+            override fun decode(buf: B): HypixelVersionedPacketData<T> {
+                if (!buf.readBoolean()) {
+                    return errorCodec.decode(buf)
+                }
+                val version = buf.readVarInt()
+                val versionCodec = versions[version]
+                    ?: return HypixelUnknownVersion(version)
+                return HypixelSuccessfulResponse(versionCodec.decode(buf))
+            }
+
+            override fun encode(buf: B, value: HypixelVersionedPacketData<T>?) {
+                error("Cannot encode a hypixel packet")
+            }
+        }
+    }
+
+    fun <B : PacketByteBuf, T> dispatchS2CBoolean(
+        ifTrue: PacketCodec<B, out T>,
+        ifFalse: PacketCodec<B, out T>
+    ): PacketCodec<B, T> {
+        return object : PacketCodec<B, T> {
+            override fun decode(buf: B): T {
+                return if (buf.readBoolean()) {
+                    ifTrue.decode(buf)
+                } else {
+                    ifFalse.decode(buf)
+                }
+            }
+
+            override fun encode(buf: B, value: T) {
+                error("Cannot reverse dispatch boolean")
+            }
+        }
+    }
+
+}
+
+
+data object PartyInfoResponseVUnknown : PartyInfoResponseV
+data class PartyInfoResponseV1(
+    val leader: UUID?,
+    val members: Set<UUID>,
+) : PartyInfoResponseV {
+    data object PartyMember
+    companion object {
+        val CODEC: PacketCodec<PacketByteBuf, PartyInfoResponseV1> =
+            CodecUtils.dispatchS2CBoolean(
+                PacketCodec.tuple(
+                    Uuids.PACKET_CODEC, PartyInfoResponseV1::leader,
+                    Uuids.PACKET_CODEC.collect(PacketCodecs.toCollection(::HashSet)), PartyInfoResponseV1::members,
+                    ::PartyInfoResponseV1
+                ),
+                PacketCodec.unit(PartyInfoResponseV1(null, setOf())))
+    }
+}
+
+
+data class PartyInfoResponse(val data: HypixelVersionedPacketData<PartyInfoResponseV>) : FirmamentCustomPayload {
+    companion object : FirmamentCustomPayloadMeta<PartyInfoResponse> {
+        override val ID: CustomPayload.Id<PartyInfoResponse> = CustomPayload.id("hypixel:party_info")
+        override val CODEC =
+            CodecUtils
+                .dispatchVersioned<PacketByteBuf, PartyInfoResponseV>(
+                    mapOf(
+                        1 to PartyInfoResponseV1.CODEC,
+                    ),
+                    HypixelApiError.createCodec("PartyInfoResponse"))
+                .xmap(::PartyInfoResponse, PartyInfoResponse::data)
+
+    }
+
+    override fun getId(): CustomPayload.Id<out CustomPayload> {
+        return ID
+    }
+}
diff --git a/src/main/kotlin/moe/nea/firmament/events/FirmamentCustomPayloadEvent.kt b/src/main/kotlin/moe/nea/firmament/events/FirmamentCustomPayloadEvent.kt
new file mode 100644
index 0000000..057fcef
--- /dev/null
+++ b/src/main/kotlin/moe/nea/firmament/events/FirmamentCustomPayloadEvent.kt
@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.events
+
+import moe.nea.firmament.apis.ingame.FirmamentCustomPayload
+
+data class FirmamentCustomPayloadEvent(
+    val payload: FirmamentCustomPayload
+) : FirmamentEvent() {
+    companion object : FirmamentEventBus<FirmamentCustomPayloadEvent>()
+}